1 #ifndef _LINUX_WAIT_H
2 #define _LINUX_WAIT_H
3
4 #define WNOHANG 0x00000001
5 #define WUNTRACED 0x00000002
6 #define WSTOPPED WUNTRACED
7 #define WEXITED 0x00000004
8 #define WCONTINUED 0x00000008
9 #define WNOWAIT 0x01000000 /* Don't reap, just poll status. */
10
11 #define __WNOTHREAD 0x20000000 /* Don't wait on children of other threads in this group */
12 #define __WALL 0x40000000 /* Wait on all children, regardless of type */
13 #define __WCLONE 0x80000000 /* Wait only on non-SIGCHLD children */
14
15 /* First argument to waitid: */
16 #define P_ALL 0
17 #define P_PID 1
18 #define P_PGID 2
19
20 #ifdef __KERNEL__
21
22 #include <linux/config.h>
23 #include <linux/list.h>
24 #include <linux/stddef.h>
25 #include <linux/spinlock.h>
26 #include <asm/system.h>
27 #include <asm/current.h>
28
29 typedef struct __wait_queue wait_queue_t;
30 typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key);
31 int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
32
33 struct __wait_queue {
34 unsigned int flags;
35 #define WQ_FLAG_EXCLUSIVE 0x01
36 struct task_struct * task;
37 wait_queue_func_t func;
38 struct list_head task_list;
39 };
40
41 struct wait_bit_key {
42 void *flags;
43 int bit_nr;
44 };
45
46 struct wait_bit_queue {
47 struct wait_bit_key key;
48 wait_queue_t wait;
49 };
50
51 struct __wait_queue_head {
52 spinlock_t lock;
53 struct list_head task_list;
54 };
55 typedef struct __wait_queue_head wait_queue_head_t;
56
57
58 /*
59 * Macros for declaration and initialisaton of the datatypes
60 */
61
62 #define __WAITQUEUE_INITIALIZER(name, tsk) { \
63 .task = tsk, \
64 .func = default_wake_function, \
65 .task_list = { NULL, NULL } }
66
67 #define DECLARE_WAITQUEUE(name, tsk) \
68 wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
69
70 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
71 .lock = SPIN_LOCK_UNLOCKED, \
72 .task_list = { &(name).task_list, &(name).task_list } }
73
74 #define DECLARE_WAIT_QUEUE_HEAD(name) \
75 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
76
77 #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
78 { .flags = word, .bit_nr = bit, }
79
80 static inline void init_waitqueue_head(wait_queue_head_t *q)
81 {
82 q->lock = SPIN_LOCK_UNLOCKED;
83 INIT_LIST_HEAD(&q->task_list);
84 }
85
86 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
87 {
88 q->flags = 0;
89 q->task = p;
90 q->func = default_wake_function;
91 }
92
93 static inline void init_waitqueue_func_entry(wait_queue_t *q,
94 wait_queue_func_t func)
95 {
96 q->flags = 0;
97 q->task = NULL;
98 q->func = func;
99 }
100
101 static inline int waitqueue_active(wait_queue_head_t *q)
102 {
103 return !list_empty(&q->task_list);
104 }
105
106 /*
107 * Used to distinguish between sync and async io wait context:
108 * sync i/o typically specifies a NULL wait queue entry or a wait
109 * queue entry bound to a task (current task) to wake up.
110 * aio specifies a wait queue entry with an async notification
111 * callback routine, not associated with any task.
112 */
113 #define is_sync_wait(wait) (!(wait) || ((wait)->task))
114
115 extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
116 extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
117 extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
118
119 static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
120 {
121 list_add(&new->task_list, &head->task_list);
122 }
123
124 /*
125 * Used for wake-one threads:
126 */
127 static inline void __add_wait_queue_tail(wait_queue_head_t *head,
128 wait_queue_t *new)
129 {
130 list_add_tail(&new->task_list, &head->task_list);
131 }
132
133 static inline void __remove_wait_queue(wait_queue_head_t *head,
134 wait_queue_t *old)
135 {
136 list_del(&old->task_list);
137 }
138
139 void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key));
140 extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
141 extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
142 void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
143 int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
144 int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
145 void FASTCALL(wake_up_bit(void *, int));
146 int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
147 int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
148 wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));
149
150 #define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
151 #define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
152 #define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
153 #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
154 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
155 #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
156 #define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
157 #define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)
158
159 #define __wait_event(wq, condition) \
160 do { \
161 DEFINE_WAIT(__wait); \
162 \
163 for (;;) { \
164 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
165 if (condition) \
166 break; \
167 schedule(); \
168 } \
169 finish_wait(&wq, &__wait); \
170 } while (0)
171
172 #define wait_event(wq, condition) \
173 do { \
174 if (condition) \
175 break; \
176 __wait_event(wq, condition); \
177 } while (0)
178
179 #define __wait_event_timeout(wq, condition, ret) \
180 do { \
181 DEFINE_WAIT(__wait); \
182 \
183 for (;;) { \
184 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
185 if (condition) \
186 break; \
187 ret = schedule_timeout(ret); \
188 if (!ret) \
189 break; \
190 } \
191 finish_wait(&wq, &__wait); \
192 } while (0)
193
194 #define wait_event_timeout(wq, condition, timeout) \
195 ({ \
196 long __ret = timeout; \
197 if (!(condition)) \
198 __wait_event_timeout(wq, condition, __ret); \
199 __ret; \
200 })
201
202 #define __wait_event_interruptible(wq, condition, ret) \
203 do { \
204 DEFINE_WAIT(__wait); \
205 \
206 for (;;) { \
207 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
208 if (condition) \
209 break; \
210 if (!signal_pending(current)) { \
211 schedule(); \
212 continue; \
213 } \
214 ret = -ERESTARTSYS; \
215 break; \
216 } \
217 finish_wait(&wq, &__wait); \
218 } while (0)
219
220 #define wait_event_interruptible(wq, condition) \
221 ({ \
222 int __ret = 0; \
223 if (!(condition)) \
224 __wait_event_interruptible(wq, condition, __ret); \
225 __ret; \
226 })
227
228 #define __wait_event_interruptible_timeout(wq, condition, ret) \
229 do { \
230 DEFINE_WAIT(__wait); \
231 \
232 for (;;) { \
233 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
234 if (condition) \
235 break; \
236 if (!signal_pending(current)) { \
237 ret = schedule_timeout(ret); \
238 if (!ret) \
239 break; \
240 continue; \
241 } \
242 ret = -ERESTARTSYS; \
243 break; \
244 } \
245 finish_wait(&wq, &__wait); \
246 } while (0)
247
248 #define wait_event_interruptible_timeout(wq, condition, timeout) \
249 ({ \
250 long __ret = timeout; \
251 if (!(condition)) \
252 __wait_event_interruptible_timeout(wq, condition, __ret); \
253 __ret; \
254 })
255
256 #define __wait_event_interruptible_exclusive(wq, condition, ret) \
257 do { \
258 DEFINE_WAIT(__wait); \
259 \
260 for (;;) { \
261 prepare_to_wait_exclusive(&wq, &__wait, \
262 TASK_INTERRUPTIBLE); \
263 if (condition) \
264 break; \
265 if (!signal_pending(current)) { \
266 schedule(); \
267 continue; \
268 } \
269 ret = -ERESTARTSYS; \
270 break; \
271 } \
272 finish_wait(&wq, &__wait); \
273 } while (0)
274
275 #define wait_event_interruptible_exclusive(wq, condition) \
276 ({ \
277 int __ret = 0; \
278 if (!(condition)) \
279 __wait_event_interruptible_exclusive(wq, condition, __ret);\
280 __ret; \
281 })
282
283 /*
284 * Must be called with the spinlock in the wait_queue_head_t held.
285 */
286 static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
287 wait_queue_t * wait)
288 {
289 wait->flags |= WQ_FLAG_EXCLUSIVE;
290 __add_wait_queue_tail(q, wait);
291 }
292
293 /*
294 * Must be called with the spinlock in the wait_queue_head_t held.
295 */
296 static inline void remove_wait_queue_locked(wait_queue_head_t *q,
297 wait_queue_t * wait)
298 {
299 __remove_wait_queue(q, wait);
300 }
301
302 /*
303 * These are the old interfaces to sleep waiting for an event.
304 * They are racy. DO NOT use them, use the wait_event* interfaces above.
305 * We plan to remove these interfaces during 2.7.
306 */
307 extern void FASTCALL(sleep_on(wait_queue_head_t *q));
308 extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
309 signed long timeout));
310 extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
311 extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
312 signed long timeout));
313
314 /*
315 * Waitqueues which are removed from the waitqueue_head at wakeup time
316 */
317 void FASTCALL(prepare_to_wait(wait_queue_head_t *q,
318 wait_queue_t *wait, int state));
319 void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q,
320 wait_queue_t *wait, int state));
321 void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait));
322 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
323 int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
324
325 #define DEFINE_WAIT(name) \
326 wait_queue_t name = { \
327 .task = current, \
328 .func = autoremove_wake_function, \
329 .task_list = { .next = &(name).task_list, \
330 .prev = &(name).task_list, \
331 }, \
332 }
333
334 #define DEFINE_WAIT_BIT(name, word, bit) \
335 struct wait_bit_queue name = { \
336 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
337 .wait = { \
338 .task = current, \
339 .func = wake_bit_function, \
340 .task_list = \
341 LIST_HEAD_INIT((name).wait.task_list), \
342 }, \
343 }
344
345 #define init_wait(wait) \
346 do { \
347 (wait)->task = current; \
348 (wait)->func = autoremove_wake_function; \
349 INIT_LIST_HEAD(&(wait)->task_list); \
350 } while (0)
351
352 /**
353 * wait_on_bit - wait for a bit to be cleared
354 * @word: the word being waited on, a kernel virtual address
355 * @bit: the bit of the word being waited on
356 * @action: the function used to sleep, which may take special actions
357 * @mode: the task state to sleep in
358 *
359 * There is a standard hashed waitqueue table for generic use. This
360 * is the part of the hashtable's accessor API that waits on a bit.
361 * For instance, if one were to have waiters on a bitflag, one would
362 * call wait_on_bit() in threads waiting for the bit to clear.
363 * One uses wait_on_bit() where one is waiting for the bit to clear,
364 * but has no intention of setting it.
365 */
366 static inline int wait_on_bit(void *word, int bit,
367 int (*action)(void *), unsigned mode)
368 {
369 if (!test_bit(bit, word))
370 return 0;
371 return out_of_line_wait_on_bit(word, bit, action, mode);
372 }
373
374 /**
375 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
376 * @word: the word being waited on, a kernel virtual address
377 * @bit: the bit of the word being waited on
378 * @action: the function used to sleep, which may take special actions
379 * @mode: the task state to sleep in
380 *
381 * There is a standard hashed waitqueue table for generic use. This
382 * is the part of the hashtable's accessor API that waits on a bit
383 * when one intends to set it, for instance, trying to lock bitflags.
384 * For instance, if one were to have waiters trying to set bitflag
385 * and waiting for it to clear before setting it, one would call
386 * wait_on_bit() in threads waiting to be able to set the bit.
387 * One uses wait_on_bit_lock() where one is waiting for the bit to
388 * clear with the intention of setting it, and when done, clearing it.
389 */
390 static inline int wait_on_bit_lock(void *word, int bit,
391 int (*action)(void *), unsigned mode)
392 {
393 if (!test_and_set_bit(bit, word))
394 return 0;
395 return out_of_line_wait_on_bit_lock(word, bit, action, mode);
396 }
397
398 #endif /* __KERNEL__ */
399
400 #endif
401
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